#include <signal.h>
#include <errno.h>
#include "syscall.h"

int sigaltstack(const stack_t *restrict ss, stack_t *restrict old)
{
    if (ss) {
        if (!(ss->ss_flags & SS_DISABLE) && ss->ss_size < MINSIGSTKSZ) {
            errno = ENOMEM;
            return -1;
        }
        if (ss->ss_flags & SS_ONSTACK) {
            errno = EINVAL;
            return -1;
        }
    }
    return syscall(SYS_sigaltstack, ss, old);
}
